Current methods for completing hydrocarbon wells often involve pumping fracturing fluids into several production zones of a well. In order to improve efficiency of this process, ball-actuated frac sleeves were invented. The ball-actuated frac sleeve has side ports that block fluid access to a production zone with which it is associated until an appropriately sized frac ball is pumped down from the surface to open the sleeve. The frac ball lands on a seat in the ball-actuated frac sleeve and frac fluid pressure on the frac ball forces the side ports in the frac sleeve to open and provide fluid access to that production zone.
Although frac balls can be dropped through a surface valve, this is a slow process that is a danger to operators if any mistake is made. Consequently, mechanisms for dropping or injecting frac balls in an appropriate size sequence into a frac fluid stream have been invented. However, such mechanisms are subject to mechanical failure and/or operator error. As is well understood, a frac ball dropped out of sequence is very undesirable because one or more zones are not fractured and the ball-actuated sleeves associated with those zones are left closed, so expensive remediation is required.
There therefore exists a need for a ball drop wellhead control apparatus that provides a ball controller between a frac ball drop or frac ball injector and a stimulation fluid stream that is being pumped into a hydrocarbon well.